Stanford engineers have invented a coating material that can help cool buildings by radiating heat away from the buildings and sending it directly into the cold of space, according to Stanford News.
The ultrathin, multilayered material acts as both a radiator and a reflector of light. The material sends invisible, infrared, heat-bearing light into space. It also reflects virtually all of the incoming sunlight that strikes it.
The result is what the Stanford team calls photonic radiative cooling: offloading infrared heat from within a building while also reflecting the sunlight that would otherwise warm it up. It’s a means to passively cool structures by radiating heat into space.
The scientists say the material sends infrared light away from buildings at the precise frequency that allows it to pass through the atmosphere without warming the air, using the cold of space as an unlimited expanse to dump heat.
The researchers say they designed the multilayered material, which is thinner than a piece of aluminum foil, to be cost-effective for large-scale deployment on building rooftops.
In addition to saving air conditioning costs of large commercial buildings, the photonic radiative cooling might also offer a cooling technology for off-grid buildings.